Download Junctional EB- Herlitz

EB
encompasses many clinically
distinctive disorders with 3 features
in common:
 Genetic
transmission
 Blister formation
 Mechanical fragility of the skin
3
major forms of inherited EB
 Simplex
 Junctional
 Dystrophic
 First
described by von Hebra in 1870
 Simplex and dystrophic separated by
Hallopeau in 1898
 Junctional EB described by Herlitz in
1935
 National EB Registry established in 1986
 Prevalence
estimate in 1990 was 8.22
per million
 5 year incidence estimates:
19.6 per
one million live
 births
 EB simplex is most common
 Recessive dystrophic EB is least
common
 Mutations
epidermis

of structural proteins of the
EBS

Intraepidermal tonofilaments- K5, 14

Junctional EB

Intralamina lucida- anchoring filaments and
hemidesmosome, laminin 5, BP Ag 2, α6 β4
integrin
 Dystrophic

EB
Sublamina densa- anchoring fibrils, collagen VII
 Intraepidermal
split
 Keratins 5 and 14 (basal layer)
 11 subtypes known, but 4 main AD
inherited
 4 subtypes
 Weber- Cockayne




Koebner
Dowling- Meara
EBS with mottled pigmentation
Rare subtype of EBS with muscular
dystrophy-defect in plectin
Localized recurrent bullous eruption on hands and
 feet
 Can appear as chronic form in infancy or later
in
 life
 Exacerbated in hot weather or with prolonged
 walking- i.e. military
 May have hyperhidrosis
 Intraepidermal and suprabasal- no scarring
 Tx:
Drysol bid can reduce blistering; treat
infection

Generalized form
 1/ 500,000 births
 Vesicles, bullae, and milia over hands, elbows,
knees, feet
 Birth or soon after
 Recurs when child begins to crawl or walk
 Worse in the summer
 Lesions are sparse with no severe atrophy
 Usually no mucous membrane or nail involvement
 Tx:
treat local infection, avoid trauma

 Circinate
configuration in infancy
 May have milia, but no scarring
 Oral mucosa is involved
 Nails shed and can regrow
 Blistering improves with age
 May have hyperkeratosis of palms and
soles after 6- 7
 y.o.
 Clumped tonofilaments
on EM
 One
Swedish family
 Scattered hyper- and hypopigmented
macules
 Mottled pigmentation fades after birth
 Seasonal blisters in acral areas
 Vacuolization of the basal layer
 Autosomal
recessive
 Widespread blisters at birth
 Absent plectin in skin and muscles

Scarring, milia, atrophy, nail dystrophy,
dental
 anomalies, laryngeal webs, urethral
strictures
 Muscular dystrophy begins in childhood or
later
 Generalized
bruising and hemorrhagic blisters
 Autosomal dominant
 Small, acral, sanguinous blisters at birth
 Autosomal
recessive
 Intralamina lucida split
 3 subtypes
Herlitz (JEB gravis)- laminin 5
 Non-Herlitz (generalized atrophic benign)laminin 5 or
 BP Ag 2
 JEB with pyloric atresia- α6 β4 integrin

 Severe
generalized blistering
 May be present at birth
 May be fatal within a few months due to
extensive
 denudation
 Relative sparing of hands
 Perioral and perinasal hypertrophic
granulation tissue
 No scarring or milia
Enamel hypoplasia and pitting of teeth
 Laryngeal and bronchial lesions can cause
 respiratory distress and potentially be fatal
 Can affect GI tract, gallbladder, cornea, vagina
 After infancy- growth retardation, refractory
 anemia
 Mutations in polypeptide subunits of laminin 5
 LAMA3
 LAMB3
 LAMC2

 Wound
care and infection control
 May use epidermal autografts of cultured
 keratinocytes of uninvolved skin grown on
collagen
 sponges
 Onset
at birth
 Generalized blisters and atrophy
 Mucosal involvement
 Dystrophic or absent nails
 Atrophic alopecia
 Enamel defects
 Reports of multiple SCCs
 Patients often survive to adulthood
 Hemidesmosomes
reduced or absent
 Mutations in COL17A1-encoding for BP Ag
2